Apparatus for sealing off the strata in a well bore



Sept. 7, 1937.

A. L. ARMENTROUT ET A1.y 2,092,041 l A' APPARATUS SEALING OFF THE STRATAIN A WELL BORE Filed July 1935 2 sheets-sheet 1 giga f 0 Sept. `1937. AA. 1 ARMENTRQUT ET, AL y l24,092,041

APPARATUS FOR SEALING OFF` THE STRATA INA WELL BORE Filed July S, 1955k2 ySheets-Sheet 2 Patented Sept. 7, 1937 Wi, s:

APPARATUS Fon'sEALING oFF THE STRATA 1N `il WELL Bons Arthur L.Armentrout, Bakersfield, and Elwin B. Hall, Los Angeles, Calif.,assignors, by mesne assignments, to `Security Engineering Co., Inc.,Whittier, ,(lalif., a. corporation of y California applicati@ 'July/"5,1935, serial No. 29,989`

5 claims.

This inventionjrelates to a method and apparatus for lexcludingencroaching fluids from a Well* A general object of this invention is toprovide a rapid, practical and inexpensive meth- 5 od for sealing orshutting oil water ornotherunf desirable fluids from ,a Well and toprovide a simple, practical and effective apparatus for carrying outsaid method.

In the drilling of deep wells'such as oil wells` l and gas wells, thebore often penetrates strata bearing water and/or water withv a smallpor-` It` is usually necessary tion of oil and/or gas. to exclude theseundesired encroaching fluids from the well. For example, where a watersandy lor a stratum bearing water is located either above or below aproductive oil orv gas stratum f in relatively close proximity thereto,it' is desrable to exclude or seal ofi the water from the Well withoutsealing ofi the `'productive stratum' 20 or strata. Heretofore muchdifficulty hasbeen encountered in excluding or sealing oi encroachy ingfluids from wells.

An object of thisl invention'is to provide a simple method by`meansofwhich encroaching fluid or a liner or other subsequentoperations'. Upon the completion of the method of thepresent inventionthe ywater or encroaching iiuid` is fullyv 3 and dependably sealed fromthe well and the well tions of the bore.

Another object of this invention is toprovide' 4 a method for excludingvfluids from a Wellthat fere with'or obstruct subsequent operations.-Another'y object of this invention is to provide a method for sealingwater and the like :from

v 45 deep wells that may be employed to seal off.

vthe encroaching fluid at any point in the open wellbore as required,and that may be employed to seal leaking casing.

Another object of this invention is -to provide 50 a method o'f thecharacter mentioned that may be easily [and quickly carried out with aminimum number of simple operations.

` Another object of this invention is to provide apparatus useful inexcluding encroaching fluids 5 irom a well that comprises a frangible orfriable sequent passage of tools, the setting of casing 'rhas enteredthe well bore.

,and below the stratum S may be considered as shale, or the like, whilethe stratum B below the bore at that point is clear and unobstructed,being of the same diameter as the adjacentl por-l doesnot necessitatethe setting of metal casing, metal liners or other metal parts likely tointer' member that may be drilled from the well when the' water bearingsand has been cemented oi leavingthe well bore entirely clear'and'unobstructed.

' Another object of the invention is to provide apparatus useful inexcluding fluid-from a well that assures the proper placementland'idistribution of the sealing cement.

A further object of the invention is to provide an apparatus for use inexcluding water or other fluid from a well-that is very simple andinexpensive of manufacture.

'The various objects andfeatures of the invention will be fullyunderstcodfrom-the following detailed description of va typical mannerof carrying out the method and a typical form 'of the invention,throughout which description reference is made to the accompanying.'

' at the point of entrance of fluid .to the well. Fig. V2 is aview'similar to Fig. il illustrating the friable member and its basketsin positionto re- Vceive the cement. Fig'. 3 is a view similar toFig. l2showing the cement filling the "member and expanding the baskets tooccupy'the enlargement ortcavity and Fig. 4 is a view similarfto Fig. 3illustrating a 4drill'drilling out` the friable memf-ber and the excesscement in the well.

In the drawings the well bore B passes'through or.v penetrates a stratumS that bears water or otherl undesired iiuid which is entering or whichThe vstrata A above lower stratum A may be considered as a productivesand bearing oil or gas, or both. y

,. present invention will be better understood after reference has-beenmade to the apparatus employed in performing or carrying `out themethod. Accordingly wewill proceed with a detailed description of atypical embodiment of the apparatus and will then describe rthe methodas carried out in employing the apparatus. The apparatus provided by theinvention and employed in carrying out rthe method of the inventionincludes, generally, an underreamer IU for enlarging the well bore B atthe stratum S,

va tubular string II adapted to; berun into the well, a drillable orfriable perforate member I2 detachably connectedwith the lower eridofthe stringk I I, a basket I3 on the member I2 to receive cement forfilling the enlargement or cavity C made by the underreamer I0, and adrill D for drilling up the member I2 and the cement re' maining thereinand remaining in the well bore 5 proper following the setting of thecement.

The invention contemplates the employment of any desired form or type oiunderreamer for making the enlargement or cavity C in the well bore atthe water bearing stratum s. It is preferred to employ an underreamercapable of making an enlargement or cavity C considerably larger indiameter than the well bore B. The particular underreamer IIIillustrated is intended merely to be illustrative of a typical tool ofthis l5 class and includes a body I4 carrying a plurality of cutters I5mounted to expand or move outwardly. As shown in Fig. 1, the cutters I5are in their expanded positions. The underreamer bodyl I4 is attached tothe lower end of a drilling string. or operating string IB and theunderreamer is operated by rotation of the string in the usual manner.Before running the underreamer I0 into the well it is preferred todefinitely locate the stratum S bearing the water or encroaching fluid.'I'his location of the stratum S may be accomplished by any of the wellknown methods. It may be preferred to carry or extend the cavity Cbeyond the upper and lower limitsof the stratum S, as illustratedthrough- 3 out the drawings. After forming the cavity C the cutters I5are retracted and the underreamer is removed from the well bore on theoperating string I8. Y

The string II is provided to run the friable member I2 into the well andto conduct the cement to the member. In accordance with the inventionthe string Il is tubular and may be made up of a plurality of lengths ofpipe or tubing.

'I'he member I2 is an important feature of.

the present invention. The member I2 is an elongate part proportioned tobe received in the well bore B with suitable clearance. The friablemember I2 is preferably suiiiciently long to extend beyond the upper andlower limits of the cavity C when in its proper position or location inthe well bore B. A longitudinal opening I1 enters the member I2 from itsupper end and extends to a point adjacent the lower end of the member.The lower end of the opening I1 is closed and a tapered or rounded noseI8 is provided on the lower end of the member to guide it ln the wellboreA B. The upper en'd I9 of the member I2 is preferably tapereddownwardly and inwardly for the purpose tolbe hereinafter described. Inaccordance with the -invention the member I2 is releasably connectedwith the lower end of the string I I to have its opening I1 incommunication withthe opening of the string. In practice the member- I2may be releasably connected with the string I I in any suitable manneror by means of any suitable device; for instance, by a releasableadapter, a safety joint, or by left hand threads 2li as illustrated inthe drawings. The threads 20 being left hand threads may be easilyreleased or unthreaded without loosening the usual right hand threads4in the string II. The invention provides a plurality ofcircumferentially and longitudinally spaced ports 2i in the wall of themember I2. It is a feature of the present invention that the member I2is drillable or friable being formed of cement, Bakelite, hard andbrittle rubber composition, glass, ceramic material, or any othermaterial that may be readily broken up or drilled up by drilling aocaontools. Owing to the fact that the member I2 is encased in cement when itis to be drilled up it may be desirable to form the member I2 of cement,it being understoood that the member may beformed of any material thatis readily drilled up, as just described.

In the preferred form of the invention illustrated means is provided-forpreventing a reverse or upfiow of cement from the opening I1 to thestring II and to prevent the loss of pressure on the cement in theopening I1 and the cavity C. I have shown a check valve arranged in theupper portion of the opening I1 to prevent the reverse flow of cementand the loss of pressure on the cement. The particular check valveillustrated includes a seat 22 arranged across the upper portion of theopening I1. 'I'he seat 22 is frangible or friable, being formed ofcement, or the like, and is provided with a central opening 23. A ball24 is provided to seal upwardly against the seat 22 to close its opening23. The ball 24 may be formed of hard rubber or a suitable composition.A cage is provided to hold the ball 24 when in its open position. Thecage may comprise wires 25 having their ends embedded in the seat 22 orthe menber l2. 'I'he ball 24 is adapted to seal upwardly against theseat 22 by internal pressure in the opening I1.

The basket I3 is provided to receive the cement asit discharges from theports 2| and is operable to expand into the cavity C by the internalpressure of the cement to hold the body of cement in the cavity C andprevent its loss longitudinally in the well bore. The basket I3 includesa main skirt or main basket part 26 surrounding the member I3 andextending throughout the perforated portion of the member. The mainbasket part 26 is preferably formed of rubber to be expansible or ii'desired the part 26 may be formed of canvas, in which case it isinitially pleated to be expansible. 'I'he lower end Portion of thebasket part 26 closely embraces the member I2 at a point below thelowermost ports 2l. A band 21 or other means may be employed to hold thelower end portion ofthe basket part 26 in tight engagement with theexternal surface of the member i2 so that it is closed against theleakage of the cement.V The main basket part 26 extends upwardly somedistance beyond the .uppermost ports 2 I.

The basket I3 includes an upper apron or skirt 28 which extends into theupper end of the main basket part 26. By this arrangement the basket I3includes two overlapping or telescoping basket sections making it suchas to readily expand and conform with the bore into which it is forced.'I'he skirt 28 may be formed of rubber or canvas and is adapted toexpand outwardly as the basket becomes filled wth cement. It ispreferred that the skirt 28 extend downwardly a considerable distanceinto the main basket part 26 .to prevent the upward escape of cementfrom the `interior of the basket. A band 29 or other means may securethe upper end of the skirt 28 to the member I2. A plurality of spacedopenings 30 may be provided ln the main basket part 26 to discharge alimited amount of cement into the stratum S in the event that thestratum S is porous to absorb the cement. The openings 30 are preferablyspaced a considerable distance fromthe opposite ends of the basket toprevent the leakage of the cement into the well bore B.

The drill D is employed to drill up the friable member I2 and the cementremaining within the member I2 and surrounding the member in the wellbore proper following the cementing operation. The inventioncontemplates the employment of any suitable form of drill for drillingup the iriable member I2 and the excess cement 5` remaining in the wellbore. `It may be foundfdesirable to employ a pilot bit or a diamondpoint bit of the type illustrated which is operable to Y first enter theprojecting upper end of the member I2 and then cut away the member andthe l excess cement as it is fed downwardly.l The diamondpoint drill Dillustrated. in the drawings is adapted to berun into the well bore on`an operating string or drilling string` 32. The drill D has a pointedlower end 33 having downwardly 15 `and inwardly inclined cutting edges34. The i drill D has the usual. discharge ports 35 for the discharge ofthe circulation uid during' drilling.

It may be preferred to employ a drill D having an eilective diameterequal to the diameter of the 20 well bore -B so that it is operabletodrill out all the cement in the Well bore proper leaving the boreclear and unobstructed. i

It is believed that the operation of the apparatus will be readilyunderstood from the following detailed description of the method of thepresent'invention as carried out with the apparatus. The method of thisinvention as practiced with the apparatus described above includes,generally, forming an enlargement or cavity C in the wall of the wellbore B at the stratum S bearing the encroaching iiuid, positioning aperforate friable member I2 and a cement basket I3 in the well bore B atthe cavity C, passing or delivering cement 40 to'the member I2 and thebasket I3 to expand thebasket and illlr the cavity C, allowing thecement 40 to set, and then drilling out the friable member I2 and moreor less of the cement in the well bore B to leave the desired size ofbore and to leave 40 a shell or lining 4I of cement in the cavity C toshut oi theencroaching nuid from the well bore.

'I'he forming of the enlargement or cavity C may be readily accomplishedby the underreamer I0 or by an equivalent tool. The underreamer I0 45 isrun into the well bore B on the string I 6` to the previously locatedstratum S and the string is operated to expand the cutters I5 and isthen rotated and fed downwardly so that the cutters I5 form the cavityC. It is preferred to extend 50 the cavity C beyond the upper and lowerlimits of the stratum S so that the lining 4I of cement is anchored inthe hard strata A. Following the forming or drilling of `the cavity Cthe underreamer I0 is withdrawn from the well bore on the 55 operatingstring I6.

Following the drilling of the enlargement or cavity C in the wall of thewell bore B the friable perforate member I2 is run linto the well on thestring I l to a position such as illustrated in Fig. 2

80 of the drawings. The member I2 is attached to lthe lower end of thestring II by the left hand threads 20 or other suitable connecting meansand the string I I is run into the well in the usual `-manner toproperly position the member I2 in 65 the well bore Where it extendsthrough the cavity C to project beyond the upper and lower extremitiesof the cavity. Afterthe member I2 has been positioned the inventionprovides for the delivering of cement to the member to expand its basket70 I3. The cement may be delivered or passed to the member I2 by meansof any of the well known methods, for example, the cement may bedelivered to the member I2 in a drop bottom bailer or by the Perkinsmethod. It is preferred to 75 pump the cement into the member I2 or putthe cement under pressure so that it flows through the ports 2| into thebasket I3 under a suitable pressure. The cement readily passes the checkvalve 24 and then flows through the opening I1 to pass out through theports 2I into the basket.

The cement under pressure entering the basket I3 expandsthe main basketpart k26 and the skirt 2B. The basket part 26 and the skirt 28 areexpanded outwardly until they bear with pressure against and conform tothe walls of the cavity C. In the event that the stratum S is porous thecement passes out through the openings 30 into the stratum. A sufiicientquantity of cement 40 is delivered to the member I2 to fully `expand thebasket I3 against thewalls of the cavity C and rto flow into thestratumS until the stratum has absorbed suicient cement. It is preferred toemploy a quick setting cement so that the body of cement in the basketand encasing the member I2 will quickly harden or set. When the basketI3 has been properly expanded and the stratum S lled with cement untilit no longer absorbs the cement, the pressure may be removed from thecement allowing the valve 24 to close against the seat 22. The cementthat may remain in the string II is then removed as by bailing. Thevalve 24 closed against the seat 22 maintains the pressure on the bodyof cement 40 and prevents the upflow of the cement into the string I I.Following the cementing operation the string II is released from themember I2 and withdrawn from the well bore. The cement 40 is thenallowed to set or harden.

The final step of the method is the drilling up of part or all of thefrangible member I2 and the cement remaining in the well bore proper.This may be readily accomplished'by any suitable form of drilling tool.It is preferred, however, to employ a rotary drilling tool so that thebody of cement 40 is not shattered. In most instances it may bepreferred to employ a pilot drill or a diamond point drill of the typeillustrated. A pilot drill or the diamond point drill D first entersYthe opening I1 of the projecting upper portion of the member I2, Thetapered upper end I9 of the member I2 guides the entering end 33 of thebit into the opening I1. As the bit or drill D is rotated and feddownwardly it drills away the friable member I2 and the cement 40 withinthe member and the portion of the body of cement immediately surroundingthe member. When the drill D is of the same eil'ective diameter as theadjacent portions of the well bore B it drills an opening 42 in the bodyof cement 40 of the same diameter as the well bore, leaving a lining orsleeve 4I of cement in the cavity C which fully shuts oil' the iluld inthe stratum S. The drill D is capable of drilling out the entire memberI2 and the excess cement 40 in the well bore forming an opening 42 ofthe same diameter as the well bore B. The basket part 26 and the skirt28 in being formed of rubber or canvas are readily cut or drilled awayby the drill D without endangering the cement sleeve 40 occupying thecavity C. After the drill D has drilled through the body of cement 4I!and has fully drilled away the frlable member I2 it is removed from thewell bore on its operating string 32 leaving the well bore clear andunobstructed for further operations. The

cement lining or sleeve 40 left in the cavity C effectively shuts orseals off the undesired fluid of the stratum S from the well bore B.

The apparatus and method provided by the present invention is adapted tobe employed for sealing leaking well casing. When employed for n 'wethis purpose the member i2 with its basket i3 may be substantially asdescribed above and is positioned in the casing at the point of leakage.

The inside Wall of the casing atsaid point would i correspond to thebore at C, above described, except that it would not ordinarily be inthe form of a cavity. Cement is then delivered or passed to the memberI2 through the string I I to expand the basket i3 and pass out throughthe openings 3G. The cement leaving the openings 30 enters the crack oropening in the casing and possibly the opening behind the casing to sealthe same. The cement is preferablypumped into the member i2 or put underpressure and when a proper quantity of the cement has discharged'intothe basket I3 the pressure is removed from the cement and the string` llis detached from the member I2 and Withdrawn from the Well bore.vr

The cement is then permitted to harden or set; After the cement has set,themember I2 and the excess cement remaining within the `casing isdrilled up by means of a suitable drilling tool leaving the casing clearand unobstructed. The cement which will have entered the opening in thecasing effectively seals the casing against leakage.

Having described only a typical preferred form of the apparatus and atypical manner of carrying out the method of the invention, we do notWish to be limited or restricted to the specific details set forth, butWish to reserve to ourselves any changes or variations that may appearto those skilled in the art or fall within the scope of the followingclaims:

Having described our invention, We claim:

1. Apparatus of the character described including, an integral drillabletubular member closed at its lower end and adaptedto be run into a Well,the member having a longitudinal opening and longitudinally spacedlateral ports, and a tubular basket surrounding the member to receivecement from the ports. l

2. Apparatus useful in excluding encroaching "duid from a well includinga drillable member adapted to be run into the Well on a string, themember having a longitudinal passage for conducting cement from thestring and a plurality of longitudinally spaced lateral portscommunieating with the passage, a valve in the passage above the portsfor preventing reverse now of the cement, and a basket on the member forreceiving cement from the ports and expansible by the cementto occupy acavity in the Well IWall, the member being drillable to be drilled upafter setting of the cement.

3. Apparatus useful in excluding encroaching fluid from a wellincluding, an integral drillable member adapted to be run into the Wellon a tubular string, the member having a longitudinal openingcommunicating with the string and a plurality of vertically spacedlateral discharge ports, and a basket on the body adapted to receivecement from said ports to be expanded thereby into a cavity in the WellWall, the basket including telescoping oppositely extending expansibleskirts surrounding the body, the member being drillable to be drilled upafter setting of the cement.

4. Apparatus useful in excluding encroaching iiuid from a well includinga drillable member adapted to be run into the Well on a tubular string,the` member having a longitudinal opening for receiving cement underpressure from the string and longitudinally spaced ports for dis-,harging the cement, and a basket on the memoer for receiving the cementfrom the ports and expansible into a cavity in the Well Wall by thecement passed into it, there being openings in the basket to dischargecement into the earth formation, the member being drillable to bedrilled up after setting of the cement.

5. A device of the character described comprising, a cast drillablemember having a longitudinal opening entering its upper end andlongitudinally spaced lateral discharge ports extending outwardly fromsaid opening, the member having an integral wall closing the lower endof the opening, an expansible basket on the member for receiving cementfrom the ports, and a valve at the upper end of the passage forpreventing a return flow of iiuid therethrough.

ARTHUR L. ARMENTROUT. ELWIN B. HALL.

